The multi-layer coil separator is a new device which efficiently and rapidly separates chemical mixtures by means of partitioning between two immiscible liquids. One liquid is immobilized within a coiled column of tubing while the second liquid is pumped through the column. The technique is complementary to other chromatographic systems and has the advantage of employing no solid phase, thereby eliminating losses by adsorption. It is particularly useful for preparative purification of polar and labile substances such as natural products, amino acids and proteins. In Phase I, a modified multi-coil separator will be constructed to permit visual and photographic studies of the mixing behavior of the immiscible liquids within the column. This information will be used to design improved columns for the separator. Other studies will determine the shortest column which can be used to reliably predict the attainable resolution of a mixture using a particular solvent system. This will greatly reduce the time needed to find an optimum solvent system. A novel multi-layer trough column will be evaluated to determine if it provides increased resolving power as would be expected from present knowledge of phase mixing in coiled columns. Phase II studies will extend the visual and photographic studies on columns investigated in Phase I and will include studies on new column designs and additional solvent systems, particularly some solvent systems which behave abnormally in multi-layer coil separations. A major Phase II project will study the effect of temperature on solubility, partition coefficient and phase retention. This will culminate in a significant goal of these studies, the construction of an apparatus operable at temperatures up to 50~C which is expected to provide increased capacity and improved efficiency. In addition, a series of substances will be evaluated which will serve as standards to classify solvent systems used in countercurrent chromatography. (3)